[kexec-tools] kdump: Basic iscsi target dump support (software initiator)

[Dave Young]

commit e30ad0a4ecf55de7bc25fbc2b9e5c7edfd741983
Author: Vivek Goyal <vgoyal at redhat.com>
Date:   Fri May 25 10:40:25 2012 -0400

    kdump: Basic iscsi target dump support (software initiator)
    
    BZ: 822701
    
    This patch implements basic software iscsi dump support. Complex iscsi
    setups like ibft etc might not work.
    
    iscsi self configuration logic is currenlty part of kdump module. At some
    point of time I would like to see it in dracut iscsi module instead of
    kdump module when iscsi and other subsystems become self configuration aware
    for general boot.
    
    This patch will require work for complex setups. Some of them are.
    
    - IPV6 support
    - IBFT support
    - Parsing some more advanced parameters and passing to netroot option.
    
    Signed-off-by: Vivek Goyal <vgoyal at redhat.com>
    Acked-by: Dave Young <dyoung at redhat.com>

 dracut-module-setup.sh |  131 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 131 insertions(+), 0 deletions(-)
---
diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
index 5dcdfc5..154faab 100755
--- a/dracut-module-setup.sh
+++ b/dracut-module-setup.sh
@@ -108,6 +108,132 @@ kdump_install_conf() {
     inst "/tmp/$$-kdump.conf" "/etc/kdump.conf"
 }
 
+kdump_iscsi_get_rec_val() {
+
+    local result
+
+    # The open-iscsi 742 release changed to using flat files in
+    # /var/lib/iscsi.
+
+    result=$(/sbin/iscsiadm --show -m session -r ${1} | grep "^${2} = ")
+    result=${result##* = }
+    echo $result
+}
+
+kdump_get_iscsi_initiator() {
+    local _initiator
+    local initiator_conf="/etc/iscsi/initiatorname.iscsi"
+
+    [ -f "$initiator_conf" ] || return 1
+
+    while read _initiator; do
+        [ -z "${_initiator%%#*}" ] && continue # Skip comment lines
+
+        case $_initiator in
+            InitiatorName=*)
+                initiator=${_initiator#InitiatorName=}
+                echo "rd.iscsi.initiator=${initiator}"
+                return 0;;
+            *) ;;
+        esac
+    done < ${initiator_conf}
+
+    return 1
+}
+
+# No ibft handling yet.
+kdump_setup_iscsi_device() {
+    local path=$1
+    local tgt_name; local tgt_ipaddr;
+    local username; local password; local userpwd_str;
+    local username_in; local password_in; local userpwd_in_str;
+    local netdev
+    local idev
+    local netroot_str ; local initiator_str;
+    local netroot_conf="${initdir}/etc/cmdline.d/50iscsi.conf"
+    local initiator_conf="/etc/iscsi/initiatorname.iscsi"
+
+    dinfo "Found iscsi component $1"
+
+    # Check once before getting explicit values, so we can output a decent
+    # error message.
+
+    if ! /sbin/iscsiadm -m session -r ${path} >/dev/null ; then
+        derror "Unable to find iscsi record for $path"
+        return 1
+    fi
+
+    tgt_name=$(kdump_iscsi_get_rec_val ${path} "node.name")
+    tgt_ipaddr=$(kdump_iscsi_get_rec_val ${path} "node.conn\[0\].address")
+
+    # get and set username and password details
+    username=$(kdump_iscsi_get_rec_val ${path} "node.session.auth.username")
+    [ "$username" == "<empty>" ] && username=""
+    password=$(kdump_iscsi_get_rec_val ${path} "node.session.auth.password")
+    [ "$password" == "<empty>" ] && password=""
+    username_in=$(kdump_iscsi_get_rec_val ${path} "node.session.auth.username_in")
+    [ -n "$username" ] && userpwd_str="$username:$password"
+
+    # get and set incoming username and password details
+    [ "$username_in" == "<empty>" ] && username_in=""
+    password_in=$(kdump_iscsi_get_rec_val ${path} "node.session.auth.password_in")
+    [ "$password_in" == "<empty>" ] && password_in=""
+
+    [ -n "$username_in" ] && userpwd_in_str=":$username_in:$password_in"
+
+    netdev=$(/sbin/ip route get to ${tgt_ipaddr} | \
+        sed 's|.*dev \(.*\).*|\1|g' | awk '{ print $1; exit }')
+
+    kdump_setup_netdev $netdev
+
+    # prepare netroot= command line
+    # FIXME: IPV6 addresses require explicit [] around $tgt_ipaddr
+    # FIXME: Do we need to parse and set other parameters like protocol, port
+    #        iscsi_iface_name, netdev_name, LUN etc.
+
+    netroot_str="netroot=iscsi:${userpwd_str}${userpwd_in_str}@$tgt_ipaddr::::$tgt_name"
+
+    [[ -f $netroot_conf ]] || touch $netroot_conf
+
+    # If netroot target does not exist already, append.
+    if ! grep -q $netroot_str $netroot_conf; then
+         echo $netroot_str >> $netroot_conf
+         dinfo "Appended $netroot_str to $netroot_conf"
+    fi
+
+    # Setup initator
+    initiator_str=$(kdump_get_iscsi_initiator)
+    [ $? -ne "0" ] && derror "Failed to get initiator name" && return 1
+
+    # If initiator details do not exist already, append.
+    if ! grep -q "$initiator_str" $netroot_conf; then
+         echo "$initiator_str" >> $netroot_conf
+         dinfo "Appended "$initiator_str" to $netroot_conf"
+    fi
+}
+
+kdump_check_iscsi_targets () {
+    # If our prerequisites are not met, fail anyways.
+    type -P iscsistart >/dev/null || return 1
+
+    kdump_check_setup_iscsi() (
+        local _dev
+        _dev=$(get_maj_min $1)
+
+        [[ -L /sys/dev/block/$_dev ]] || return
+        cd "$(readlink -f /sys/dev/block/$_dev)"
+        until [[ -d sys || -d iscsi_session ]]; do
+            cd ..
+        done
+        [[ -d iscsi_session ]] && kdump_setup_iscsi_device "$PWD"
+    )
+
+    [[ $hostonly ]] || [[ $mount_needs ]] && {
+        for_each_host_dev_fs kdump_check_setup_iscsi
+    }
+}
+
+
 install() {
     kdump_install_conf
     inst "$moddir/monitor_dd_progress" "/kdumpscripts/monitor_dd_progress"
@@ -119,4 +245,9 @@ install() {
     inst "/bin/cut" "/bin/cut"
     inst "/sbin/makedumpfile" "/sbin/makedumpfile"
     inst_hook pre-pivot 9999 "$moddir/kdump.sh"
+
+    # Check for all the devices and if any device is iscsi, bring up iscsi
+    # target. Ideally all this should be pushed into dracut iscsi module
+    # at some point of time.
+    kdump_check_iscsi_targets
 }